Typically, integrated circuits such as rapid chips, structured ASICs, or field programmable devices allow chip designers to configure input/output (IO) devices during metallization or programming steps. For wirebond packages, this flexibility is assisted by a system of bond pads and signal fingers that electrically couple IO devices to the package. Each signal finger is hardwired via pad wire to a bond pad of the package. Some of the bond pads are configured for power/ground connections while others are configured for signal IO. Flipchip based designs work in a similar manner except the signal fingers and pad wire are replaced by flipchip bumps.
Power and ground connections for configurable IO devices and the core area have defined ratios and/or counts. The slice designer chooses these counts during the base layer creation of the design. The power/ground pad counts are derived by examining typical applications to make an engineering choice on a fixed number. The counts cannot be configured by the customer. This means that a high speed IO application with low signal count, which demands more IO and power/ground pad counts than is available on the slice, may not be compatible with the package. Conversely, a lower speed IO application, which requires a large signal count but not all power/ground pad counts available on the slice, may not be compatible with the package. Therefore, performance is limited. A similar scenario applies to core power and ground supplies. A small core content may not justify all core power and ground supplies. Conversely, a large core content or speed may demand more power and ground pads which would not be available, thus limiting the chip core performance.
Accordingly, it is desirable to provide a method for configuring the power and ground counts after slice creation to comply with customer requirements.